PP Film Blowing Machine1. This screw material cylinder is elabroately made of 38CRMOALA alloy steel after nitrogen treatment and has best rigidity and corrosion resistance.2. The mould head is plated with hard chroming and has screw mandrel structure with uniform and smooth material discharing. And the aircooled device has labyrinth lype structure with characteristic as uniform air-jut quantity, automatic temperature control and automatic heating.